Nowadays, the control of power factor correction circuit is mainly performed by a correction control module, as mentioned in patents TW I459696, TW I466428, TW I590574, and CN1753290. Power factor adjustment by the correction control module is mainly based on an input voltage, an output voltage and an operating current of the power factor correction circuit. However, since the input voltage of the power factor correction circuit used by a power supplier is as high as 380 V, the operating current of the power factor correction circuit is small. The circuit mode of the existing correction control module is unable to properly adjust when the operating current becomes small, so that the control of the power factor and current harmonic distortion cannot be effectively improved.